4月24 在线词典 （老师的源码）

这个是客户端。========================================================
=================================================================

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <strings.h>
#include <sqlite3.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define  N  256
#define  R  1 // user register
#define  L  2 // user login
#define  Q  3 // query word
#define  H  4 // history record

typedef struct sockaddr SA;

typedef struct
{
    char type;
    char name[N];
    char data[N]; // password or word or remark
} MSG;

void do_register(int sockfd, MSG *buf);
int do_login(int sockfd, MSG *buf);
void do_query(int sockfd, MSG *buf);
void do_history(int sockfd, MSG *buf);

int main(int argc, char *argv[])
{
    int sockfd;
    struct sockaddr_in servaddr;
    char clean[N];
    MSG buf;

    if (argc < 3)
    {
        printf("Usage : %s  \n", argv[0]);
        exit(-1);
    }

    bzero(&buf, sizeof(MSG));

    if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("fail to socket");
        exit(-1);
    }

    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = PF_INET;
    servaddr.sin_port = htons(atoi(argv[2]));
    //这里要注意inet_addr()里面是255.255.255.255  和  里面写的不对时候的返回好像都是-1;
    servaddr.sin_addr.s_addr = inet_addr(argv[1]);


    if (connect(sockfd, (SA *)&servaddr, sizeof(servaddr)) < 0)
    {
        perror("fail to connect");
        exit(-1);
    }

    int n;
    while ( 1 )
    {
        printf("************************************\n");
        printf("* 1: register   2: login   3: quit *\n");
        printf("************************************\n");
        printf("please choose : ");
        if (scanf("%d", &n) == 0) //匹配失败的时候，返回为0，输入的字符进入了stdin 的缓冲区
        {
            fgets(clean, N, stdin);    //这里要将缓冲区里面的“不正确的字符”给吃掉
            printf("\n");
            continue;
        }
        switch ( n )
        {
        case 1 :
            printf("\n");
            do_register(sockfd, &buf);
            printf("\n");
            break;
        case 2 :
            printf("\n");
            if (do_login(sockfd, &buf))
                goto next;
            printf("\n");
            break;
        case 3 :
            close(sockfd);
            exit(0);
        }
    }
next:
    while ( 1 )
    {
        printf("************************************\n");
        printf("* 1: query word   2: History   3: quit *\n");
        printf("************************************\n");
        printf("please choose : ");
        if (scanf("%d", &n) == 0)
        {
            fgets(clean, N, stdin);
            printf("\n");
            continue;
        }
        switch ( n )
        {
        case 1 :
            printf("\n");
            do_query(sockfd, &buf);
            printf("\n");
            break;
        case 2 :
            printf("\n");
            do_history(sockfd, &buf);
            printf("\n");
            break;
        case 3 :
            close(sockfd);
            exit(0);
        }
    }




    exit(0);
}

void do_register(int sockfd, MSG *buf)
{
    buf->type = R;
    printf("input name:");
    scanf("%s", buf->name);

    printf("input passwd:");
    scanf("%s", buf->data);

#ifdef _DEBUG_
    printf("type=%d name=%s data=%s\n", buf->type, buf->name, buf->data);
#endif

    send(sockfd, buf, sizeof(MSG), 0);

    bzero(buf, sizeof(MSG));
    recv(sockfd, buf, sizeof(MSG), 0);
    printf("reply-%s\n", buf->data);
}

int do_login(int sockfd, MSG *buf)
{
    buf->type = L;
    printf("input name:");
    scanf("%s", buf->name);

    printf("input passwd:");
    scanf("%s", buf->data);

#ifdef _DEBUG_
    printf("type=%d name=%s data=%s\n", buf->type, buf->name, buf->data);
#endif

    send(sockfd, buf, sizeof(MSG), 0);

    bzero(buf, sizeof(MSG));
    recv(sockfd, buf, sizeof(MSG), 0);
    printf("reply-%s\n", buf->data);

    if (strcmp(buf->data, "OK") == 0)
        return 1;
    else
        return 0;
}

void do_query(int sockfd, MSG *buf)
{
    while (1)
    {
        buf->type = Q;
        printf("input word:");
        scanf("%s", buf->data);
        if (strcmp(buf->data, "#") == 0)
            break;

        send(sockfd, buf, sizeof(MSG), 0);

        bzero(buf, sizeof(MSG));
        recv(sockfd, buf, sizeof(MSG), 0);
        printf("%s\n", buf->data);
    }
}

void do_history(int sockfd, MSG *buf)
{
    buf->type = H;

    send(sockfd, buf, sizeof(MSG), 0);

    while (1)
    {
        bzero(buf, sizeof(MSG));
        ssize_t n = recv(sockfd, buf, sizeof(MSG), 0);
        printf("n=%d data=%s\n", n, buf->data);
        if (n == -1)
        {
            perror("recv");
            exit(-1);
        }
        if (strcmp(buf->data, "#") == 0)
        {
            printf("data-%s\n", buf->data);
            break;
        }
        printf("%s\n", buf->data);
    }
}

这个是服务器==============================================================
======================================================================

#include <stdio.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sqlite3.h>
#include <signal.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define  N  256
#define  R  1 // user register
#define  L  2 // user login
#define  Q  3 // query word
#define  H  4 // history record

typedef struct sockaddr SA;

typedef struct
{
    char type;
    char name[N];
    char data[N]; // password or word
}MSG;

void do_register(int connfd, MSG *buf);
void do_login(int connfd, MSG *buf);
void do_query(int connfd, MSG *buf);
void do_history(int connfd, MSG *buf);

int main(int argc, char *argv[])
{
    int listenfd, connfd;
    struct sockaddr_in myaddr;
    pid_t pid;
    ssize_t n;
    MSG buf;

    if (argc < 3)
    {
        printf("Usage : %s  \n", argv[0]);
        exit(-1);
    }

    if ((listenfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("fail to socket");
        exit(-1);
    }

    bzero(&myaddr, sizeof(myaddr));
    myaddr.sin_family = PF_INET;
    myaddr.sin_port = htons(atoi(argv[2]));
    myaddr.sin_addr.s_addr = inet_addr(argv[1]);

    if (bind(listenfd, (SA *)&myaddr, sizeof(myaddr)) < 0)
    {
        perror("fail to bind");
        exit(-1);
    }

    if (listen(listenfd, 5) < 0)
    {
        perror("fail to listen");
        exit(-1);
    }

    signal(SIGCHLD, SIG_IGN); //子进程死了的时候会变成僵尸进程，
    while ( 1 )                    //这里是交个操作系统来解决这个问题
    {
        if ((connfd = accept(listenfd, NULL, NULL)) < 0)
        {
            perror("fail to accept");
            exit(-1);
        }
        if ((pid = fork()) < 0)
        {
            perror("fail to fork");
            exit(-1);
        }
        else if (pid == 0) //这里是并发服务器，
        {
            close(listenfd);    //在子进程中要关掉监听listenfd套接字
            while(1)
            {
                bzero(&buf, sizeof(buf));
                n = recv(connfd, &buf, sizeof(MSG), 0); //在服务器里收到的字符的个数
                printf("n=%d type=%d name=%s data=%s\n", n, buf.type, buf.name, buf.data);
                if (n == 0) //对于tcp连接来说，客服端close的时候，
                    break;
                switch (buf.type)
                {
                case R: do_register(connfd, &buf); break;
                case L: do_login(connfd, &buf); break;
                case Q: do_query(connfd, &buf); break;
                case H: do_history(connfd, &buf); break;
                }

            }
            close(connfd);
     exit(0);
     }
        close(connfd); //在父进程中要关闭连接connfd套接字
    }

    exit(0